Two celestial spheres dominate this engraved scientific illustration, the upper one marked with surface features and surrounded by smaller orbital diagrams, while the lower sphere sits majestically within a thin ring, its geography rendered in fine cross-hatching against cream paper. The composition follows the formal structure of 18th-century natural philosophy, with lettered reference marks positioned above and below the main forms to denote comparative scales and astronomical relationships. Printed on smooth white card stock and made to order, artwork on the front, blank inside, envelopes included in every set. A handwritten note that arrives as an independent artist's work.